Chemistry environmental project – real numbers that will make your students think about their small actions.

There is a steady increase in environmental issues in the curriculum every year. The environment is important and we must take care of it, thus teaching about it to students that will one day take care of the world is a necessity.

But whenever I learned about it or taught it, I found it to be more of a “social studies” subject and not a science. There’s a lot of descriptions, definitions of concepts, discussions of alternatives, debates. It never felt like a real “science”, with numbers, predictions, experiments, etc. I know that this is not the case. I know that environmental sciences are very much scientifically based and hard core, with lots of experiments and empirical data supporting phenomena, but the way the curriculum has the “environment” presented wasn’t at all interesting to me thus far (since I’m one of those science geeks).

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Genetic Algorithm Game: a great way to show the application of evolution to high school students

A while back I was in a situation where I had to teach evolution to some grade nine students. I am more of the physical science/math teacher, and biology is not my cup of tea.

In physics, there are also unproven “theories” that we follow. In fact, all of Newtonian physics is pretty much “false” and yet we teach it all the time as fundamental physics. Light is both a wave and a particle… how can that ever be possible? Either it can travel through objects (like a wave / energy) or it is stopped by objects (like a particle)? For some reason, the physical theories don’t affect people in the same emotional way as the theory of evolution. We have a way of dealing with the physics theories on a logic / thinking level. No religion is offended (although ~400 years ago, Copernicus’ theory of planetary motion around the sun was dissputed by the Catholic church). Nobody’s extreme beliefs come under fire with all these silly physics theories.

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How to teach kids long subtraction with borrowing

Recently I taught my son (grade 2) how to do subtraction of large numbers with borrowing. I am a high school math teacher, so I thought that teaching this subject would be a piece of cake. However, I didn’t realize that I would have to be this creative in order to actually get through to my son. Anyway, my method worked like a charm, so I’m posting it. It’s pretty basic, and I’m sure it has been widely used by good teachers (that really understand how to teach kids math), but in case you haven’t thought of this method, here it is.

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Math Teacher’s Bag-of-Tricks: How to make my class more entertaining?

Math can sometimes seem like a very dry subject… you can just have a pencil and paper to do it, and in order to become good at it, you need to do problem after problem: “Practice Makes Perfect” as they say. But as a math teacher, it is nice to have a bag of “math tricks” up your sleeve to show the actual beauty and interesting side of math.

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The Sword of Knowledge: A Cute Puzzle – Great for Kids!

The dragon of ignorance has three heads and three tails. However, you can slay it with the sword of knowledge by cutting off all its heads and tails. With one swipe of the sword you can cut off one head, two heads, one tail, or two tails.

But . . .

When you cut off one head, a new one grows in its place.

When you cut off one tail, two new tails replace it.

When you cut off two tails, one new head grows.

When you chop off two heads, nothing grows.

Help the world by slaying the dragon of ignorance.

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Interesting Puzzle- how does this work?

1. Take an eight by eight grid (with 64 squares).
2. Fill it randomly with digits 1 through 8.
3. Now start at any number on the left most column.
4. Move that many spaces down your grid (going up to the top of the next column if you run out of space).
5. Whatever number you land on, take that many steps down the grid, moving to the top of the next column if you run out of space, and continue.
6. Continue this procedure, until you run out of room on the whole grid.
7. Mark the last spot you landed on.
8. Start again with a new number on the left most column of your grid. Redo the whole procedure.
9. Try again, starting with yet another number on the left most column of the grid. And again. And again.
10. What happened?

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Building houses of straw, sticks, and bricks – The Three Little Pigs lesson plan

Keeping with the theme of building, my last workshop for the younger elementary students was about building structures of different materials. I first read the kids the classic tale of the Three Little Pigs. This is an amazing little story that can be used as a starting point for a Scientific Method / Building Lesson Plan.

After that we discussed the different materials that were used to build the three houses. I asked the kids to make a hypothesis whether the story is correct. Here are some questions we discussed:

  • Which house is really the best one? Why do you think so?
  • What is the manipulated variable in this story? What is the responding variable? What about the controlled variables?
  • How could we test out the hypothesis? How many times would we have to do the experiment to feel satisfied that the story is correct or incorrect?

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Teaching Hydraulics and Pneumatics Unit to Children

Hydraulics and Pneumatics are great topics to teach children.  First of all both words sound very impressive and when the children learn these words they will sound very important and knowledgeable if they use them.  Also,  hydraulics and pneumatics are used in many machines and in many everyday applications, therefore it is easy to show the importance of understanding these topics.  One can easily show and explain the difference between hydraulics and pneumatics – a great “Compare and Contrast” analysis. Thirdly, there are many fun and impressive experiments that can be done with hydraulics and pneumatics in a very inexpensive way, with very accessible materials.  And finally, since hydraulics and pneumatics is so useful, there can be multiple projects that children can actually build themselves.  Thus weaker students and stronger science students can both do projects, yet with differing complexity. Here are some of the techniques I use in order to teach hydraulics and pneumatics to children:

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Does frequency of light affect the current of the Photoelectric Effect?

This week, one of my students challenged my understanding of the photoelectric effect… Basically, he didn’t think that the current produced by the photoelectric effect should be affected by the frequency of the photons, but only by the intensity of the light. After a while, he convinced me – more photons per second (the intensity) should mean more electrons per second, but why would the speed of the electrons have an effect on the current?

However, from the PHET simulation of the photoelectric effect as well as the experimental results of a photoelectric device we have at school, it was obvious that current should be affected by frequency. I looked on the internet for a possible explanation… I couldn’t find anything reasonable. I even looked at the spectrum of our light used in the experiment, thinking that the intensity of the blue light was larger than the intensity of the red light – but no, that wasn’t the case.

So I asked an expert – Dr. Friesen, the professor responsible for the Modern Physics course at the University of Calgary. He was kind enough to reply with an incredibly clear explanation.

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